Empty containers, such as PET (polyethylene terephthalate) bottles, are typically used for storing a liquid beverage before the liquid is consumed. Such containers may become contaminated with foreign material, such as paper, wood dust, or plastic debris during shipping, even when they are stored in boxes or other carrying receptacles. The bottles can also become contaminated as they are being processed prior to filling. Moreover, during processing, contact between the containers and the surfaces of articles, such as conveyors or carriers, used to convey the containers, cause the containers to pick up a small amount of net electrostatic charge, thereby rendering the containers capable of attracting fine particles to the containers' internal and external walls. Additionally, the electrostatic charges on the bottles may cause the bottles to cling to one another, thus causing the bottles to move at an angle. This leads to bottles falling off of the conveying system, particularly when using a belt or rope conveying system. Thus, the need to rinse or otherwise clean the containers prior to filling is necessary to ensure that the contents of the beverage within the container are acceptable to the ultimate consumer.
Typical dust particles contaminating these containers are extremely small, often measuring less than 10 microns in diameter. Any electrostatic charges on the containers induce opposite charges on the particles to attract and hold the particles on the container walls. To remove particles adhering to the walls, these opposite charges must be neutralized. Neutralizing the charges is difficult, however, because the charges holding each dust particle to a container wall are shielded by the dust particle itself. Moreover, once the electrostatic forces have been momentarily abated, the freed dust particles must be removed immediately before they re-attach themselves to the container.
Several methods have been implemented to rinse the inside of a container or bottle. The methods include spraying the containers with cold or hot water, utilizing ozone or ozonated water as a sanitizing agent, using ionized gas streams to rinse containers, and using combinations of air and water for rinsing.
Examples of utilizing ionized gas streams systems for rinsing containers are disclosed in U.S. Pat. No. 7,621,301 to Wu et al. and U.S. Publication No. 2009/0101178 to Wu et al., which are fully incorporated by reference. These systems can have many applications in cleaning unwanted particles from containers. For example, these systems can be used in conjunction with a hot fill, ambient fill, cold fill, or aseptic fill applications.